As noted in the above, VietTorrent *IS* currently "Open Signup" (which is a pretty straight forward involving creating your login/pass and verifying your e-mail address), however, UNLIKE most trackers there is a "2nd activation" page that is REQUIRED to be able to UL or DL any content...it took me a few weeks to figure out my way past that point, and in the hope of saving others that same headache:
In the previous "VietTorrent | HD | General || 2013 Review||" there are a couple of comments that I felt would make for SOLID and helpful transplants...

So, I wanted to take just a moment to follow-up regarding the "2nd activation" REQUIRED to DL from VietTorrent. From what I have best been able to put together (mostly through Google translate), I believe the first two options are a couple of different "PAID" options (and as entirely unattractive as a subscription model would be to me for this sorta thing already...I seem to recall reading somewhere, that these two paid options may be specifically localized to Vietnam residents ONLY). The 1000 bonus point option is a NON-paid option in place as an incentive for members to actively contribute content (AFTER successful "2nd activation").
Also on this "2nd activation" page is an e-mail address that is provided to be able to reach VietTorrent regarding this "2nd activation". Previously, I had dismissed this e-mail address as simply being "tech support" for their PAID subscription options...but last night I just decided to drop them a line (basically saying that while I would NOT be interested in any paid option, I would very much welcome and appreciate the opportunity to join and actively contribute to their community and then earn the right to continue through their bonus points system)
...and it worked! I received a courteous reply from a VietTorrent staff member less than 6 hours later who had activated my account for the next 3 months (just as I had requested)! :D
Their e-mail address is indicated on the "2nd activation" page (and, the initial activation round was totally open sign-up at least when I created my account a couple/few months back), but just to make it readily available...it is: viettorrent.sp@gmail.com
Good luck and I hope this supplemental helps to at least get ya a foot in the door and make a go of it from there!
All the best!
-A.E.